The present invention relates to fittings, particularly but not exclusively for fastening cabling and/or pipework in the aerospace field.
Metal fittings are well known to the person skilled in the art, e.g. for the purpose of fastening cabling and/or pipework. In the present context, the term “cabling” means not only electric cables, but also other filamentary devices such as optical fibers, for example. In the present context, the term “pipework” means not only ducts for conveying fluid, but also other types of hollow duct, such as heat pipes and/or waveguides, for example.
Such fittings typically comprise a bracket with two flat segments that are joined together along an edge, forming an angle less than 180° on an inside of the bracket and an angle greater than 180° on an outside of the bracket. Typically, the inside angle is about 90° and the outside angle is about 270°.
In applications that are subjected to high levels of vibration, it is normal practice to use stiffeners in order to offset the resonant frequencies of such a fitting so as to avoid it entering into resonance with such vibrations. Without such a stiffener, such resonance could lead to premature breakage of the fitting by vibration fatigue.
Typically, such fittings are made of metal, and the stiffener is welded to the bracket. Nevertheless, that presents the drawback of relatively heavy weight. In particular for aerospace applications, the use of a large quantity of such metal fittings leads to a large increase in weight, to the detriment of the performance of the vehicle in which such fittings are included.
Proposals have also been made, for example in international patent application WO 2007/078272 A2, to use composite materials for producing such a fitting with a stiffener. Nevertheless, the proposed production methods involve a production cost that is rather high.